Dental chair



4 Sheets-Sheet 1. L. STUCK.

DENTAL CHAIR.

(No Model.)

Patented Oct. 18, 1892.

WITNESSES.

ATTORNEY.

(No Model.) 4 SheetsSheet 2.

L. STUCK.

DENTAL CHAIR.

No. 484,747. Patented Oct. 18, 1892.

1? gm (@TTORNEY.

W N?! R (No Model.) 4 Sh'eetsSheet 3.

L. STUCK.

DENTAL 0114114.

No. 484,747. Patented 044. 18, 1892:.

I BY

ATTORNEY.

4 Sheets-Sheet 4. L. STUCK. DENTAL CHAIR.

(No Model.)

No. 484,747. Patented 001;. 18, 1892.

. NITED STATES LEVI STUCK, OF BAD AXE, MICHIGAN, ASSIGNOR TO AARON P. GOULD, JOHN PATENT Fries.

O. SKELTON, AND ALBERT IIOEFFER, OF CANTON, OHIO.

DENTAL CHAIR.

SPECIFICATION forming part of Letters Patent No. 484,747, dated October 18, 1892. Application filed September 4, 1890. Serial No. 363,896. (No model.)

T0 at whom it may concern.-

Be it known that I, LEVI STUCK, a citizen of the United States, and a resident of Bad Axe, county of Huron, State of Michigan, have invented a new and useful Improvement in Dental Chairs, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, making part of this specification.

My invention relates to improvements in dental chairsand head-rests therefor; and it consists in certain features of construction and combinations of parts, as will be hereinafter described, and pointed outin the claims.

Figure l of the accompanying drawings is a view in perspective illustrating my invention. Fig. 1? is a vertical sectional view through the supporting-base. Fig. 2 is aperspective view of the under side of the foot rest. Fig. 3 is a similar view from above of a fragment of the foot-rest. Fig. 4 is a simi lar view of the hoisting mechanism from below, enlarged. Fig. 5 is a similar view of the lowering mechanism from the side, enlarged. Fig. 6 is a plan view of the same, enlarged. Fig. 7 is a view in cross-section of the friction ring or cylinder. Fig. 8 is a perspective view of the lower end portion of the chair-support and the adjustable foot-piece by which the standard or support is adjusted and connected with the lowering device. Fig. 9 is a perspective of the head-rest and support. Fig. 10 is a similar view of the sphere or ball, by which a universal joint is formed between the pad-support and clamping-plates. Fig. 11 is a similar view of the top plate. Fig. 12 is a similar view of the clamping-plate. Fig.

former, for the purpose of this case, cylindrical,the latter in parallelogram form. These bars are placed at opposite sides of the base and are connected by a yoke D, having at one of its ends a sleeve portion a in which is placed friction-shoes a semicircular in cross-section, to embrace the bar B and setscrews a to adjust said shoes to the bar, and at the other end portion a link a, pivotally secured to the yoke D at its inner end. The object of the link is to form a locking mechanism to arrest the downward movement of the chair-body E by grasping the opposite sides of the bar 0.

To operate the link a, a rock-shaft a is journaled in the side portions of the yoke D and is provided with a cam-face a that is to say, the face a projects a greater distance from the axis of said shaft than its opposite face. A spring a is secured by one end to the bottom of the yoke and with its free end engages the cam-face a of the shaft a and exerts its force to hold the cam-face a down.

On one end of the shaft (0 is provided a foot-lever F, the inner portion 1) thereof extending inside the axis of the shaft and on which rests one end of a lever b, the central portion of which is pivotally secured to the side of the yoke D, as shown at 19 and the end portion pivotally connected to the link a", as shown at b At the lower end of the stem or chair-body support G is provided a block I), having one of its ends adapted to engage a shoulder on the sleeve a to lift the sleeve when the stem G is raised, and at the other end a set-screw 12 having its lower end working against the bottom of the yoke. By means of this setscrcw b the block may be leveled or adjusted to the yoke D.

In operation the lever F is pressed down, which will raise the end of the lever 19, engaging said lever F, which operation will move the outer end of the link a down and release it from its bite or engagement with the bar O, thus throwing the weight of the chair-body on the sleeve portion a of the yoke D. The descent of the chair is regulated by the friction of the shoes at, adjusted by the screws a against the bar B. When the lever F is released, the spring a will rock the shaft a in the reverse direction, allowing the parts to assume the position shown in Fig. 5, the link a engaging the bar 0 to arrest the downward movement of the chair. The spring 0. assists in holding the link a in biting engagement with the bar 0. This spring is secured in any suitable manner, but preferably by having one of its ends inserted through the side of the yoke D, while its other end bears against the bottom of the link a to accomplish its object.

To raise the chair and gripping devices, a foot-lever H is provided and is pivotally secured to lugs b projecting downward from the top portion a of the base. The inner end portion of this lever is bifurcated, as shown, the prongs b embracing the stem G and hav ing secured to their ends links b the lower ends of which engage and support the liftingrings 1) on opposite sides of the stem to raise said rings obliquely to the stem, whereby the oppositeinside edges of the rings bite or engage the stem to raise it and the chair-body. A reverse movement of the foot-lever will allow the rings to drop at the same time until arrested by the stop b pending another vibration of the lever. In the act of raising the chair-body the link a alternately grasps and releases the bar Cthat is to say, while the chair-body is ascending the link a is free to slide upward on the bar 0 with the chairbody; but as soon as the operator reverses the movement of the lever H to get another hold to further elevate the chair-body the link a grasps or bites the bar 0, thus preventing a downward movement of the chair-body.

00 designates a set-screw adapted properly to space the rings during their biting engagement with stem G.

The back Tof the chair is pivotally secured to the side frames U, as shown at k, to swing forward and over and back from the seat V, and is held in desired adjustment by the swinging rack-bar said bar having a pivoted connection with the under side of the seat. The free end of the rack-bar it passes through and in locked position is engaged by a loop 70 secured to the lower portion of the back frame T.

In operation the bar is raised out of engagement with the edge of the loop and the back moved to a desired point of adjustment. The rack-bar is then dropped into engagement with the loop to hold the chair in its desired adjustment. This construction provides a quick, efiective, and inexpensive method of adjusting the back with relation to theseat.

J denotes supporting-legs secured to the seat-frame. A foot-rest is provided, consist ing of a frame d, having an angle portion (1 projecting upward between said legs, on the inside of which are provided longitudinal grooves (1 in which are placed slides (1 secured to the angle portion (1, by which the foot-rest is held out at right angles to the legrest portion (1.

On the under side of the foot-rest portion dis provided a track 01 a stop (1 and a rack d At the lower end portion of the legs J is provided a cross-shaft d upon which is p votally secured a foot-lever K, having at its 1nner end a roller 01 to travel on the track 61 To the shaft (1 is pivotally secured a springactuated dogd, the free end of which will engage the notches in the rack d To operate said dog, a trip-lever (1 is pivotally secured to the side of the lever K, as shown at d, and with its inner end engages the dog, as shown at d.

In operation when the foot-rest IS in normal position, as shown in Fig. 1, the foot of the operator is placed upon the free end of the lever K, which when pressed down will cause the roller (1 to press against the track (1 and raise the foot-board upto the position shown in Figs. 2 and 3, the dog (1 following to engage one of the teeth in the rack to hold the foot-rest at the desired point of ad ustment. With the foot on the leverK the toe or other portion of the foot may be brought in contact with the trip-lever, by which the dog may be disengaged from the rack and" the foot-rest lowered.

Another featureof my inventio uis the-headrest, which is constructed as follows: P represents the head-rest support, the lower por tion of which is secured to the back of the chair and is adapted for vertical ad ustment. The pad-frame Q is provided with diverg ng arms h and a neck portion h, terminatmg in a ball or sphere h plate R is placed in and under a hollow top plate S, the plus it on plate R passing through the perforations h in plate S, which perforations are large enough to allow the-pins h on the plate It to enter therein at an angle in putting the parts together, and also to allow a vertical play of one plate on the other in the operation of clamping the members of the headrest, previous to which the ball h is placed in a hemispherical socket 71 in the clamping-plate R, the neck It being secured to said ball in any suitable manner after it and the-whole being secured by the handle nut h as shown in Figs. 1, 9, and 16. To prevent the bolt turning in the supporting-plate P, it is provided with a squared shoulder h. The plates R and S are put together so as to clamp the ball h in the socket h, the notched or free end of the plate It extending slightly below the lower edge of the top plate S, so that when the top plate is drawn down over the plate R the ball will be clamped in the socket h between the plates S and at the same time be secured to the support P.

In operation, to adjust the head-rest the handle-nut is turned to slack the bolt h after which the arm, composed of the plates R and S, may be rotated about the bolt or moved lat- A bottom or clamping ;has been placed in the socket. A bolt h passes through the aperture 72, and notch h" of the plates 8 and R, respectively, through the slot in the supporting plate P,

orally in the slot in the support P or the padframe rocked in the socket. The parts are then secured together in the desired adj ustment by the bolt h'.

I claim as new- 1. The combination, with a supporting-base, of bars B and G, secured therein, a yoke D, having a sleeve portion to embrace the bar B, a link pivotally secured to the yoke to normally bite or clamp the bar 0, a body-supporting stem G, supported by said yoke, and means for releasing the biting engagement of the link with said bar 0, substantially as set forth.

2. The combination,with the base A, of the bars B and O, a yoke D, having a collar or sleeve a embracing one of said bars, a link pivoted to said yoke and normally clamping or biting the other bar, a stem G, having secured to its lower end a block b, seated in said yoke and engaging With one end the collar or sleeve a whereby when the stem is raised the block will lift said yoke with it and free the link from its biting engagement with its bar, and a screw 6 whereby said parts may be adjusted one to the other.

3. The combination, with a chair-body, of foot-rest-su pporti n g legs having guideways, a foot-rest having projections to slide in said ways, a track 01 on the under side of said footrest, a rack d adjacent thereto, a cross-bar 62 secured to the lower end of said legs, a footlever K, supported thereon, the inner end of which is provided with a roller d to travel on said track, a dog to engage said rack, and a trip carried by the foot-lever to disengage said dog from said rack.

4:. The combination, in a head-rest, of the supporting-arm composed of the plate or cap S, having an aperture 72, and perforations it, and at its other end an aperture 78*, a plate R, adapted to fit within the cap S, said plate having at one of its ends a socket 77, and outwardly-projected pin or pins to pass into the perforations h, a ball k to rest in the socket it, and perforation h, and a pad-frame secured thereto, and a bolt h to clamp said cap and plate on said ball and to the head-rest support.

In testimony whereof I have hereunto set my hand this 11th day of July, A. D. 1890.

LEVI STUCK. Witnesses:

ALLISON L. WRIGHT, CHARLES E. THOMPSON. 

